Tuesday, December 1, 2009

Potpourri

* A fantastic Richard Lindzen op ed. Sometimes I think the climate change skeptics I respect the most don't make their strongest points in a pop forum. But this one is out of the park. My favorite part, which needs some explanation:

The IPCC's Scientific Assessments generally consist of about 1,000 pages of text. The Summary for Policymakers is 20 pages....However, it has been my experience that even the summary is hardly ever looked at. Rather, the whole report tends to be characterized by a single iconic claim.

The main statement publicized after the last IPCC Scientific Assessment two years ago was that it was likely that most of the warming since 1957 (a point of anomalous cold) was due to man. This claim was based on the weak argument that the current models used by the IPCC couldn't reproduce the warming from about 1978 to 1998 without some forcing, and that the only forcing that they could think of was man. Even this argument assumes that these models adequately deal with natural internal variability—that is, such naturally occurring cycles as El Nino, the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation, etc.

Yet articles from major modeling centers acknowledged that the failure of these models to anticipate the absence of warming for the past dozen years was due to the failure of these models to account for this natural internal variability. Thus even the basis for the weak IPCC argument for anthropogenic climate change was shown to be false.

To understand Lindzen's powerful argument, you need to know exactly what it means when leading climate scientists say that there is strong evidence of "anthropogenic [manmade] global warming." Let me reproduce my earlier summary of their evidence:

Richard Lindzen...thinks that the cutting-edge models do not correctly model certain processes in the atmosphere at the "micro" level. Orthodox climatologists concede the point, but then challenge Lindzen to tweak their models in order to come up with a better simulated fit with historical observations (on temperatures, rainfall, etc.). Thus far Lindzen has been unable to do this, because the fastest computers would not be able to run a simulation of the entire world, at a scale small enough to capture the effects Lindzen points to, and obey all the laws of physics.[1] What has happened (it seems to me) is that even the latest generation of climate models necessarily make some heroic simplifying assumptions, in order to render the model tractable. Lindzen isn't accusing the modelers of being lazy. Even so, he maintains that their models are still crude and give very misleading results. The connection between the work of Paul Samuelson and, say, Israel Kirzner should be obvious.

What is particularly worrisome to me is that the case for anthropogenic global warming runs basically like this (and see the Intergovernmental Panel on Climate Change Fourth Assessment Report [IPCC AR4] section here [pdf] in their own words, especially Frequently Asked Question 9.2 on page 702): When the modelers simulate the 20th century, they achieve a closer fit to the historical trends if they assume large, positive feedback effects from human greenhouse gas emissions. If the modelers adjust the dials (so to speak) and turn down the possible influence of human emissions, then, so long as we insist the models obey the laws of physics, the fit between the simulated temperatures and observed temperatures gets worse.

OK now with that background, you can understand the power of Lindzen's WSJ argument. Global temperatures have undeniably risen quickly in the 20th century. Skeptics say that we can't be sure human activities are driving this trend, because there is so much about natural variability that the computer models don't take into account. But the IPCC standard bearers come back and say these models are good enough for the purpose, and from what we know of internal, natural variability, we can't get the models to reproduce the warming of the 20th century. Only if we assume that human impacts on greenhouse gases (through emissions and cutting down forests etc.) have a large effect, can the latest computer models do a good job simulating the observed climate changes.

OK, so now Lindzen is bringing up a different point: It is well known that since 1998, global temperatures either have slightly fallen or have been flat (depending on whom you quote), even though greenhouse gas emissions grew faster than the models predicted they would. The models that the IPCC uses predicted that global temperatures would have risen from 1998 onward, of course subject to natural variability.

So what Lindzen is here claiming, is that the IPCC apologists are undercutting themselves. In order to explain away the lack of (modeled) warming in the last decade, they need to rely on a large variance in natural climate factors. But then this weakens their claim that natural variability alone is insufficient to explain the warming of the 20th century.

Before Climategate, I would have been much less likely to pay credence to Lindzen on this particular claim. I would have believed a Gavin Schmidt if he said, "We are correctly accounting for both ends of the issue, and we're in the sweet spot middle. Our models have just enough natural variability to explain the recent flat temperatures, but not enough natural variability to explain the overall warming trend in the 20th century."

Yet after seeing Michael Mann wonder aloud if he and his colleagues have actually checked that this explanation about post-1998 temperatures is consistent with their models, I am much more inclined to believe Lindzen's take.

1) It is none of the public's business what happens to athletes and other celebrities outside of their public work as athletes (or actors or whatever), unless it affects their work, a la what happened to Kudlow in the 80's at Bear Stearns because of drugs (which he discussed in the link).

The only famous people who fall in the category of "the public has a right to know" what they do during down time (i.e. their private time) is politicians.

2) Lindzen is a wonderful, highly published climate scientist who is constantly trying to poke holes in everything, which is exactly what a scientist is supposed to do. As near as I can tell he has never advocated a hypothesis that had at the time been shown to be false. In other words he is not a nutjob and this drives people like Mann and Jones batguano crazy.

One thing he has relatively recently pointed out (sorry, too lazy to try to find a link) is that the Earth is leaking a significant amount of heat none of the climate models have predicted, nor can they account for.

The climate models are garbage. Put real data into any false model and it is virtually 100% guaranteed to be wrong (in what direction who knows) with regard to future predictions.

A focus on the surface temperature record (despite the essay by Lindzen) is at best a second-rate method to track the heating effect of greenhouse gases on the climate. The best way to actually measure global warming is to look at the changes in *heat content* of the climate system. This is because heat content is a 3-dimensional field involving mass. Temperature on the other hand is a massless 2-D field, which in essense measures only an infinitely thin slice of the atmosphere near the surface. Surface temperature trends can be driven by all sorts of boundary layer meteorology effects such as changes in surface roughness and nocturnal turbulence which may have little or nothing to do with greenhouse gas forcing. There is a growing but somewhat ignored body of peer-reviewed literature showing this non-greenhouse effect on temperature may be significant.

Many scientists reporting in the actual peer-reviewed literature are now becoming much more interested in tracking ocean heat content, rather than auditing surface temperature trends (unless you pay too much attention to the Climate Audit vs Gavin Schmidt back and forth). Changes in the ocean heat content mirror the radiative flux divergence at the top of the atmosphere, since nearly all of the heat storage capacity in the climate system resides within the oceans. This means that all the processes that govern the radiative imbalance at the top of the atmosphere (weather, greenhouse gas forcing+feedbacks, aerosols, ect.) can be summed up (almost) by measuring the changes in ocean heat content in terms of Joules. By comparing changes in ocean heat content to the output of the coupled climate models, we are close to being able to produce an accurate report card grading how well the numerical model output is matching observations in terms of their radiation budget. Something to watch: Virtually all the coupled climate models show a significant positive radiative imbalance at the top of the atmosphere on annual to multi-decadal periods. No single model run realizations that I am aware of show a multi-year period without a substantial positive imbalance. This is due to the increasing dominance of GHG forcing, which now swamps natural variablity in the models. The moment of truth for gauging how well the model climates replicate the actual climate is now arriving. Over the next 5-10 years we will know with a high degree of confidence how to grade model performance. Since 2003, the Argo float array has measured temperature and salinity in the ocean down to below 700 m with unparalleled accuracy. (**Prior to the deployment of Argo in 2003, there remains large uncertainty in the technical circles whether historical ocean measurements using XBTs are accurate)

The early Argo results since 2003 paint a troubling picture for the models. The multi-year average radiative imbalances depicted by virtually all the climate models are much larger than those being measured so far in the ocean by the Argo array. Granted, the data record is still very short, but within a few years, a much clearer picture will emerge. This is why Kevin Trenberth (in some of the hacked e-mails) is concerned about the lack of ability of the models to track annual changes in the radiation budget. He knows it may point to big problems down the road, and Trenberth is at least concerned that so very few in the modeling community seem interested in answering the question *why*.

Many of us in the earth science community who are up to date on the actual peer-reviewed literature know the uncertainties. The shock of these e-mails has mainly reverberated among the casual observer and media-type who had believed the public propaganda coming from a certain cadre of activist scientists with political objectives.

I can't believe Kudlow backs up his points by citing politicians only. Since when are politicians and athletes/business men the same thing? The only part of the public that he has to care about are his fans, which will most likely love him no matter what this incident turns out to be. He has changed the game of golf for the better and that will always be his legacy.

Bob, I know you are a fan of Kudlow because he had you on his show and actually gave you a fair hearing, which was admirable for sure, but this guy is seriously one of if not the biggest tools in America.